21 - Cellular Endogenous Fluorescence: A Basis for Preparing Subpopulations of Functionally Homogeneous Cells

Abstract

This chapter reviews the technique of autofluorescence-activated cell sorting and discusses its usefulness in recognizing and isolating cell preparations with different functional properties. Earlier studies demonstrated how the measurement of the cellular FAD and NAD(P)H fluorescent intensities allows the distinction and isolation of various types of pancreatic endocrine cells. Autofluorescence-activated cell sorting permitted the preparation of pure and single insulin-containing B cells, which were used to investigate the functional properties of this cell type without interference from other cell types. In the course of these studies, it was noticed that this endocrine cell population does not represent a homogeneous group of identical cells, but rather is composed of functionally diverse subpopulations. Several of these subpopulations have been recognized during flow cytometric analysis, whereby the cellular autofluorescent compounds FAD and NAD(P)H appeared again to be particularly powerful discriminators. The observation that a pure pancreatic B-cell population is composed of functionally diverse subpopulations underlines the need to purify cells according to their functional properties rather than according to their structural characteristics.